Study On Wood Color Improving Treatment Of Plantation Eucalyptus Urophylla

The study of this dissertation is mainly pointed to the problems of wood color met in the manufacturing of wood clothes racks made of plantation Eucalyptus urophylla wood,which will made a bad visual effect after translucent painting.These wood color problems mainly contain the color difference between sapwood and heartwood,inhomogenous color,dim color and lustre,etc.In order to study how to improve the visual effect of the wood color of plantation Eucalyptus urophylla,bleaching,coloring and other methods were adopted in the experiments of wood color treatment.And the results indicate that:The color difference between sapwood and heartwood,inhomogenous color, dim color and luster,and other color defects on the plantation Eucalyptus urophylla wood could be cleared,and the color of treated wood could be improved into well-proportioned white by bleaching treatment.With chemical coloring treatment,it not only could cover up the wood color defects,but also could make some good-looking color show on the wood surface.Besides,with the treatment of dyeing solely,dyeing after bleaching and the integrative color treatment,it also had some color improving effects in a certain extent,but the effects were not better,and the treatment prescriptions and techniques were more elaborate than that of the bleaching and chemical coloring treatment.In all kinds of decolourant prescriptions adopted in the experiment,the oxidation prescriptions had better and more obvious bleaching effects than the deoxidize prescriptions.And the peroxide prescriptions had better bleaching effects than other oxidation bleaching prescriptions.The hydrogen peroxide prescriptions had better bleaching effects than other peroxide prescriptions.The prescriptions with alkali or alkaline salts as active adjuvant had better bleaching effects than other hydrogen peroxide prescriptions,and when sodium hydroxide or potassium hydroxide as active adjuvant,wood color treatments could have the best and most obvious bleaching effects.For the hydrogen peroxide prescriptions with sodium hydroxide or potassium hydroxide,the formulations and technics parameters affected greatly the bleaching effects.In technics factors,the effect of treatment temperature was maximal;the effect of treatment time was secondary;and the effect of liquor ratio was most unconspicuous.And in the formulation factors,the effect of dosage of sodium hydroxide was maximal;dosage of sodium silicate was secondary;and concentration of hydrogen peroxide was minimal.The concentration of hydrogen peroxide and treatment temperature effected greater towards bleaching rate and effected weaker towards bleaching quality.The better hydrogen peroxide bleaching formulation and technics were that:concentration of hydrogen peroxide was 40, dosage of sodium hydroxide was 5g/L,dosage of sodium silicate was 10ml/L; treatment temperature was room temperature,treatment time was 2h.When the coloring formulation,chief chemical and adjuvant of which were respectively hydrogen peroxide and chemical X,was adopted in the wood color improving treatment experiment,it not only could cover up the wood color defects,but also could make Eucalyptus urophylla wood show some good-looking color on the wood surface,which was very similar with Schima superba wood color.The treatment formulation and technics were that: concentration of hydrogen peroxide was 10%,dosage of chemical X was 40g/L; treatment temperature was room temperature,treatment time was 0.5h.When the coloring formulation,chief chemical and adjuvant of which were respectively oxalic acid and chemical Y,was adopted in the wood color improving treatment experiment,it not only could cover up the wood color defects,but also could make Eucalyptus urophylla wood show some good-looking color on the wood surface,which was very similar with mahogany wood color.The treatment formulation and technics were that:concentration of oxalic acid was 2%,dosage of chemical Y was 10g/L;treatment temperature was 90℃,treatment time was 0.5h.